Blackthorne Plans to Seize the Black Ship to Pressure the Christian Daimyo

Blackthorne’s proposal to seize the Portuguese Black Ship is an attempt to convert command of the sea into leverage in Toranaga’s political struggle. He argues that the Jesuits’ dependence on the ship’s arrival and the trade revenues it brings could make them press Christian daimyō to side with Toranaga. The plan remains a proposal, not an operation: Toranaga rejects its immediate use, and Blackthorne turns to Mariko to help change his decision.

Maritime Knowledge and the Basis of the Plan

Blackthorne’s confidence rests on a profession built around making sea routes legible. His old teacher, Alban Caradoc, taught him that ships out of sight of land could be lost because charts were vague and longitude could not be fixed. A rutter offered a practical answer: a pilot’s record of courses, depths, currents, winds, storms, anchorages, shoals, and the means of reaching and leaving a port. Such a guide could make unfamiliar waters navigable, but it was vulnerable to copying and translation errors, even deliberate ones; a pilot could not be certain of its accuracy until he had sailed the route himself. Portugal and Spain treated their rutters as national secrets, while their Dutch and English enemies sought the knowledge they contained. This history helps explain why Blackthorne sees navigation and access to ships not as technical matters apart from politics, but as sources of power.

His experience also includes the particular demands of Japanese coastal and open-water navigation. On the voyage carrying Toranaga toward Anjiro, Rodrigues took the galley down the eastern coast of the Izu Peninsula, rounded Cape Ito, and turned west-southwest across open water toward Cape Shinto. The faster offshore course saved time but left the coast’s shelter behind. Blackthorne therefore understands the practical difference between a vessel that can maneuver at sea and one constrained by speed, wind, or a dangerous approach. Later, during the escape by galley, he calculates the frigate’s need to tack into the harbor mouth against the galley’s greater freedom to maneuver, and insists that the galley hold its course despite the risk of collision. The proposal to seize the Black Ship grows out of this embodied knowledge of routes, ships, and the military consequences of controlling passage.

The Proposed Economic and Military Pressure

Blackthorne presents the Black Ship as a source of money on which the Jesuits’ work depends. He tells Toranaga that, when the ship did not arrive the previous year, the priests received no money, and argues that another absence would put their finances and Christian activity in danger. His point is not simply that capturing a valuable vessel would hurt Portugal: he wants Toranaga to use the threat to make the priests bend and to help bring Lord Onoshi, Lord Kiyama, and Lord Harima to Toranaga’s side. The ship becomes, in his reasoning, a means of applying pressure to religious intermediaries whose influence reaches into the Christian daimyō faction.

He then connects that economic pressure to military action. If Crimson Sky were launched at the same time as, or before, an attack on Nagasaki, Blackthorne proposes taking the Black Ship and striking at sea traffic between Kyushu and Honshu. He reasons that a naval threat might draw forces away from the land conflict or persuade Toranaga’s enemies to become allies. The surrounding geography matters to his calculation: Lord Harima has become hostile, while Kiyama, Onoshi, and Harima are based in Kyushu. Blackthorne believes the Erasmus could also disrupt a large transfer of troops from that island to the main island. The idea therefore joins financial coercion to control of the sea roads, rather than treating the Black Ship as a prize in isolation.

The plan collides with Toranaga’s limits on foreign violence in Japan. Toranaga has told Blackthorne that foreigners are present by permission and that public quarrels or mischief are punished by death; he also insists that Japan is not a place where foreign nations may attack one another or kill Japanese people. He distinguishes such an attack on Japanese soil from harrying an enemy of a foreign ruler on the open sea. Blackthorne’s plan, especially its proposed attack on Nagasaki, tests that boundary. Its strategic appeal does not make it acceptable to Toranaga, who is unwilling to authorize a campaign that could provoke the priests, disrupt trade, or widen the conflict on terms he has not chosen.

Toranaga’s Refusal and Blackthorne’s Appeal

When Blackthorne lays out the proposal, Toranaga listens closely, watching his lips, but asks what outcome he expects. Blackthorne names Onoshi, Kiyama, and Harima. Toranaga challenges the implication that Blackthorne should interfere in Japanese politics as the priests do, and points out that the priests claim they cannot command Christian daimyō. Blackthorne answers that money gives them power and that the prospect of losing the Black Ship’s revenues could force a change. He emphasizes the urgency of withholding the ship both this year and the next, making the threat a continuing pressure rather than a single seizure.

Toranaga refuses the immediate course. He says the priests could stop trade, that he is not at war with the priests or Nagasaki, and that he is going to Osaka; there will be no Crimson Sky. Blackthorne accepts the answer aloud, but privately judges that Toranaga has understood the possible military effect. He believes the proposal could draw a substantial portion of Kiyama, Onoshi, and Harima’s forces away from the main island and that the Erasmus could hinder their sea transfer. He does not mistake Toranaga’s understanding for permission. Instead, he tells himself to be patient and allow Toranaga time to consider the possibility.

Blackthorne soon makes a second effort through Mariko. He explains the proposal to her and says he believes he can make the priests bring Kiyama or Onoshi to Toranaga’s side if Toranaga allows him to take the Black Ship. Mariko judges the logic sound and recognizes that the hostility of Harima could provide a reason to attack if Toranaga were truly going to war rather than surrendering. She also says that bringing Kiyama or Onoshi over, together with Zataki and time, could tip the balance; at the same time, she notes that Zataki opposes Toranaga. Her response establishes that the plan has potential in the wider political calculation without erasing its conditions or risks.

The Unresolved Proposal

Blackthorne asks Mariko to help persuade Toranaga to give him the opportunity and, crucially, to delay going to Osaka. He frames the priests as his own enemy even though they are hers, and asks her to assist him in using their dependence on trade for Toranaga’s benefit. The appeal makes the plan personal as well as strategic: Blackthorne cannot authorize the seizure himself and needs Toranaga’s consent, while Mariko’s influence may help him obtain a hearing.

The evidence leaves the proposal unresolved. Toranaga has not approved the seizure, the attack on Nagasaki, or the disruption of the Kyushu–Honshu routes, and Blackthorne’s request to delay the Osaka journey is still an effort to change policy. The episode nevertheless shows how his maritime expertise enters the political contest: ships, money, ports, and troop routes become interlocking forms of leverage. His ability to imagine such pressure is real; whether Toranaga will permit him to use it is not settled here.